Hehehe… It sucks to be in the wrong place at the wrong time… and to make matters worse you're the only person around who can save the day (whether you want to or not)… :)
I tried to draw Christina from 3rd Period Lunch (she's the one in the flashback panel), but wavy hair has always been my weakness.
The other cameo is the guy handing David his gear. I don't know what his name is, but he's a teacher from “A Teacher's Woes”. That comic is from the same artist who draws the Drunkduck comic “Sex on the Beach”. :)